Containers, and more specifically metallic beverage containers, generally contain a neck on an upper portion that is adapted for interconnection to a metallic end closure. The container end closure is formed from a flat sheet of metallic material and generally includes a pull tab, ring pull, or other form of opening device. Beverage containers commonly store carbonated beverages, thus, both the container body and the container end closure are required to withhold internal pressures up to 90 psi while under varying temperatures without catastrophic failure or permanent deformation. Further, the container end closure must be manufactured, stacked, shipped, and sent to a filler prior to being seamed onto a container body filled with a carbonated beverage. Thus, the container and end closure must be designed to resist deformation and failure while utilizing thin metallic materials and allowing compact stacking during shipping and manufacturing.
Food and beverage containers with pull tabs, stay on tabs (“SOTs”), ring pulls, and pull aperture openings are generally known. Ring pulls (also called pull rings), ring pull tabs, and pull tabs are generally secured to the end closure by a rivet located in the center of the central panel, which limits the size of the opening because the opening can only extend from the periphery of the central panel to the rivet at the center of the panel. Additionally, the initial opening point is generally adjacent to the rivet, which is traditionally located in the center of the end closure. SOTs are generally secured to the central panel and rotated by a user to push the nose of the SOT on the tear panel, which is fractured from the end closure along a score line. The ring pull is secured to the end closure within the tear panel, which is defined by a score line, such that when the user pulls the ring pull tab, the score line fractures and the tear panel with the pull ring tab is torn completely off and discarded.
Known end closures with center-located rivet ring pulls have reached the limit of opening size. Thus, the opening in the end closure cannot be increased beyond current designs if the ring pull rivet is located in the center of the end closure.
Additionally, end closures may buckle when under varying temperatures and internal pressure. If an end closure buckles near the score line and opening, then the score line may crack and release the contents of the container. This is called “peak and leak.” To prevent buckling and peak and leak, end closures may be made of thicker metal. However, this approach increases production cost and the amount of force needed to fracture the score line.
An important feature of end closures is their ability to resist abuse during transport and stacking. A particular problem in this regard is the possibility that when a filled container is stacked on top of another filled container, e.g., during transport, the base of the upper container pushes down on the tab of the lower container. This can cause the score formed around the tear panel of the lower container to fracture. A known solution to this problem is to form a pair of downwardly projecting points or nibs on either side of the tab that project downward slightly further than the point of the tab nose. These additional points typically contact the surface of the end closure in the unopened configuration and, in the event of an impact on the container (e.g., due to stacking), prevent the nose from coming into contact with the end closure. When the lift ring or tail of the tab is raised to open the end closure, however, the tab pivots about these points allowing the nose to impact the end closure and fracture the score. It is possible to achieve a similar effect by providing a pair of raised dimples on the end closure, under and in contact with the tab. However, in designs that provide a circumferential bead extending behind the nose of the tab, the bead will tend to interfere with the raised dimples.
Accordingly, there exists a significant need for a container end closure with a ring pull tab that has an increased opening size, allows for faster pouring, increases access to the scent of the container's contents, enhances the content's flavor, and resists abuse during transport and stacking.
Due to the numerous limitations associated with the prior art described above, the following disclosure describes an improved container end closure that is adapted for interconnection to a container body and that employs a large opening for faster pouring. This novel design provides buckle resistance, prevents inadvertent opening, and significantly improves the end closure's pour rate.